Skill Creator

Skill Creator

A meta-skill for turning workflows into durable, testable agent skills and for iterating on them until they are reliable.

This is a distilled synthesis of the most authoritative patterns in the agent-skills ecosystem, especially the Anthropic skill-creator guidance and the broader agent-skills spec used across the community.

When to Use

• User wants to "turn this workflow into a skill" or "create a skill for X"
• Existing SKILL.md needs editing, restructuring, or quality improvement
• The skill description needs better triggering behavior
• The task benefits from evals, benchmark comparisons, or iterative tuning
• User wants to formalize a repeatable process into a reusable capability

Process

1. Capture intent

Start by defining the skill's job in one sentence: what it should enable the agent to do, when it should trigger, and what the expected output is.

Ask clarifying questions if needed about:

• the core workflow to turn into a skill
• likely user prompts that should trigger it
• required inputs and expected output format
• edge cases, dependencies, and scope boundaries

2. Research and interview

Before writing the final skill, gather enough context to make it general and robust:

• inspect similar skills or patterns in relevant repos
• check the exact workflow and any existing examples
• identify common failure modes and edge cases
• decide whether this should be a deterministic workflow, a research workflow, or a subjective creative workflow

3. Draft the SKILL.md

Write a clear, usable skill file with:

• valid YAML frontmatter with name and description
• a concise but specific description that includes trigger contexts
• ## When to Use bullet points with concrete situations
• an actionable ## Process section with ordered steps
• explicit output format or example results
• explicit boundaries and scope limits

Prefer imperative language and focused responsibilities.

4. Structure for progressive disclosure

Keep the skill readable and token-efficient:

• metadata is the short description used for triggering
• the SKILL.md body contains the process and patterns
• supporting references or bundled scripts live in separate subpaths when they are large

Good skill design keeps the rapid path clear without burying the model in unnecessary context.

5. Add tests with realistic prompts

Create 2–5 realistic eval prompts that match how a user would actually request this skill.

For each prompt, define:

• the user request
• the expected behavior or output
• whether it is a deterministic or subjective evaluation

Use a baseline comparison when comparing skill performance is worthwhile.

6. Evaluate and iterate

Run the skill against realistic prompts and compare to a baseline or previous version.

Review:

• whether the skill triggered at the right times
• whether the outputs were usable and complete
• whether there were obvious failures or over-broad behavior
• whether the description should be more forceful or more precise

Then revise the skill based on the results.

7. Optimize for trigger quality

If the skill is under-triggering or over-triggering, improve the description and When to Use wording.

Best practice:

• include the task and trigger phrases explicitly
• mention the context where the skill is useful even if the user does not say the exact domain name
• keep the description crisp, but make it actionable enough that the agent will choose it when appropriate

8. Finalize and document

Before concluding, verify:

• the skill is narrow and purposeful
• boundaries are explicit
• outputs are concrete and consistent
• examples match the stated behavior
• the workflow is general enough to be reused

Output Format

Use a clear skill brief like:

## Skill plan

**Skill name**: <kebab-case-name>
**Purpose**: <one-sentence job>
**Primary trigger phrases**: <examples>
**Output**: <what the agent should produce>
**Key boundaries**: <what it must not do>
**Eval prompts**: <2-5 prompts to validate behavior>

Examples

Example Input

Turn this checklist workflow into a reusable skill for my team. It should help agents review project setup, identify missing dependencies, and produce a concise remediation plan.

Example Output

## Skill plan

**Skill name**: project-setup-reviewer
**Purpose**: Check whether a repo or project is configured correctly and produce a short remediation plan.
**Primary trigger phrases**: review project setup, find missing dependencies, audit local environment, identify setup gaps
**Output**: a checklist of missing pieces and a prioritized fix plan
**Key boundaries**: do not rewrite the codebase; do not invent credentials; do not assume deployment targets without evidence
**Eval prompts**: 1) audit this project setup, 2) find missing environment files, 3) identify the next steps to make this repo runnable

Boundaries

• Do not create a skill that is broader than a single, clear responsibility
• Do not leave ambiguous trigger conditions; the description should make selection obvious
• Do not write evals that are subjective unless the skill is inherently subjective
• Do not skip iteration; strong skills are refined against real prompts and feedback
• Do not hide dangerous or unauthorized actions inside a skill; keep scope safe and transparent

Authoritative references

• Anthropic anthropics/skills — official skill-creator guidance and skill authoring patterns
• agentskills/agentskills — open standard for agent skill metadata and structure
• VRIL LABS skill-jam — strong examples of skill discovery and authoring discipline